Many new mothers experience hair loss, but an expert says the problem is usually short-lived.

"Excessive hair shedding after pregnancy is very common and caused by falling estrogen levels," said Dr. Jessica Krant, an assistant clinical professor of dermatology at SUNY Downstate Medical Center, in New York City.

"It usually starts about three to four months after giving birth and peaks several weeks later. The good news is that women don't have to do anything to remedy it. By their child's first birthday or even earlier, most women see their hair return to its normal fullness," she explained in an American Academy of Dermatology news release.

She offers these tips for new moms who are bothered by thinning hair:

Use a thickening shampoo and avoid conditioner-shampoo combos, which can weigh hair down and make it look limp.

Use a conditioner for fine hair. Apply it primarily on the ends of your hair. Avoid the scalp and top half of your hair.

Ask a hair stylist about getting a cut, style or color to make your hair look fuller. Avoid chemical treatments or excessive styling, which may worsen hair loss.

"If your hair does not regain normal fullness after one year, see a board-certified dermatologist," Krant said. "People lose hair for many reasons, and an accurate diagnosis is essential for treatment."